JPH02200560A - Hydraulic booster - Google Patents

Abstract

PURPOSE:To reduce the backlash at the initial stage of operation and improve operability by coupling a control member with a cylinder main body at the time of nonoperation and moving a valve body in the direction to seat the valve body on a discharge valve seat against a return spring. CONSTITUTION:When a brake pedal is returned to the original position, the pressure of a pressure chamber 29 is decreased, the first piston 19 and the second piston receive the liquid pressure of the first hydraulic chamber and the spring force of a return spring and are moved to the right to loosen a brake. The return position of an input member 9 is restricted by a stopper member 105, a recess 107 at the tip is brought into contact with the rear end of a movable valve body 97, or a gap rarely exists between them. When a device is not in operation, the rear end of the movable valve body 97 is brought into contact with a valve seat 107a formed on the recess 107 of the input member 9 or the gap between them is zero, when a brake is applied, i.e., the input member 9 starts to be moved, a discharge valve is immediately closed and a feed valve can be opened, and the operating characteristics of the brake can be made very good.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a hydraulic booster used to assist the operation of a mask cylinder or the like in a vehicle or the like.

[Prior Art] For example, a hydraulic booster disclosed in Patent No. 60-176859 includes a cylinder body in which a cylinder hole is formed,
A piston that is slidably inserted into a cylinder hole and defines a servo chamber at one end, a valve hole provided in the piston, and a pressure chamber arranged in the valve hole that communicates with an external pressure source and a pressure release source The valve device includes a valve device that controls shutoff according to an input, and a control member that fits into the valve hole and controls the input to the valve device, and the valve device is biased toward the control member by a spring and axially a movable valve body, a supply valve seat provided on an inner wall of the valve hole such that the valve body can be seated, a discharge valve seat provided on a control member such that the valve body can be seated, and the discharge valve seat and the valve body. and a return spring that biases the control member in a direction opposite to the valve body so that the control member is separated from the valve body.

[Problem that the invention seeks to solve]

However, in the above device, the discharge valve seat and the valve body are spaced apart in the axial direction to ensure a passage area necessary for loosening.

This separation distance is large, and the play at the initial stage of operation is large.

The present invention has been made in view of such problems, and an object of the present invention is to provide a hydraulic booster that reduces play during the initial stage of operation.

[Means for solving problems]

In the above-mentioned configuration, the above object is to engage the control member with the cylinder body when not in operation, and move the control member against the valve body in a direction in which the discharge valve seat and the valve body are seated against the return spring. This is achieved by a hydraulic booster that is moved by

[Function] Although the discharge valve seat and the valve body are seated, the gap between them can be reduced to almost zero. Therefore, after the movement is started by the input of the control member, the valve device is immediately operated to communicate the external pressure source and the pressure chamber, thereby reducing the operating play and increasing the braking force.

This can improve operability.

〔Example〕

Hereinafter, a hydraulic booster according to an embodiment of the present invention will be described with reference to the drawings.

In the figure, the device of this embodiment is indicated as (1) as a whole, and the mask cylinder part (3) is located on the left side of the cylinder body (2), and the details thereof are shown in Figure 2 on the right side. A booster section (4) is provided. Cylinder body (
A stepped hole (5) is formed in 2), the front end is a closed end, and the rear end opening is closed by a lid (6). The lid body (6) is fixed to the cylinder body (2) by a stop ring (4) with a seal ring (7) interposed therebetween;
Further, the entire device is fixed to a toe board (not shown).

i A shaft-shaped input member (9) is slidably fitted into the cup seal αη in the central through hole (8) of the body (a).

(In this specification, the front means the left side in the figure,
Rear shall mean to the right. ) Furthermore, the tip of the rod portion (2) of the connecting member that is fitted over the brake pedal (not shown) is received in the recess formed at the rear end of the input member (9), and the ring (6) Extraction is stopped. A boot Q4 is fixed between the rod part (end) and the rear end of the main body (2) to prevent dust.

The stepped hole (6th hole) of the cylinder body (2) consists of a large diameter hole part aη into which the lid body (6) fits and a small diameter hole part (to) that occupies most of the part. The first
The piston α field is slidably fitted, and the second piston (1) is slidably fitted to the left side of the small diameter hole (G). The first piston curve has a first large diameter part Qυ (see Fig. 2), a second large diameter part, and a third large diameter part at the rear end, middle part, and front end, respectively, and has a seal ring Q4JQ5 ( (see Figure 2), and a cup seal mark is attached. In this way, a pressureless chamber 10,000 is formed between the second large diameter part and the third large diameter part (c), and an Achiemulator pressure is formed between the second large diameter part and the first large diameter part +211. A chamber is formed. Also, the first
A boosting pressure chamber (
c) (see Figure 2) is formed.

Of the prisoners in the pressurized room, only the doctor in the non-pressure room had access to the mask cylinder part (3
), and the front half of the first piston 4 for defining this pressureless chamber mark belongs to the mask cylinder section (3), and the details of this master cylinder section (3) will be explained below. . At the front end of the first piston Q
311 is screwed on, and the head of this pole C31) is engaged with a lock-shaped spring receiver, and the shaft part is fitted with a ring-shaped spring receiver C3. Receptacle f32
A spring (b) is stretched in a compressed state between 1n, and the spring holder presses the time to the rear end of the second piston (1), and the spring holder presses the field to the front end of the first piston (40).

Moreover, the above-mentioned cup seal (■) is attached to the first large diameter part as a head formed at the front end of the first piston α9 in oil contact therewith, and the large diameter part ( To)
A first hydraulic pressure generating chamber is formed between the first piston 4 and the second piston (1) by attaching a cup seal to the piston.

2nd piston - 〇 Front end large diameter part (G) K also has a cup seal (
(71 is installed, and as a result, a pressureless chamber c39 is formed between the front end large diameter part and the rear end large diameter part (G), and the bottom wall of the piston (1) and the cylinder body (2) A second hydraulic pressure generating chamber (4I) is formed between the second piston retainer and the cylinder body (48).
2) is biased to the right by a return spring i4D stretched between the bottom wall and the bottom wall. An output port is formed at the front end of the cylinder body (2) in communication with the second hydraulic pressure generating chamber t411, and this is connected to the wheel cylinder of the front wheel via a pipe (not shown). Further, although not shown, another output port is formed in the cylinder body (2) so as to communicate with the first hydraulic pressure generating chamber 4, and this is connected to the wheel cylinder of the rear wheel via a conduit (not shown). Ru.

A boss portion 51 is provided on the earth wall at the front end of the cylinder body (2).
) is formed, and the fluid connection hole 6z communicates with the second fluid pressure generation chamber (411) through the return hole 6 (l) when the brake shown in the figure is not in operation, and communicates with the no-pressure chamber (411 through the supply hole i49). c39. Also, the liquid connection hole 521 [F
i The connecting cylindrical portion of the reservoir (b) is press-fitted through the grommet ring O.

The reservoir 64 has a known structure, and the upper opening of the cylindrical main body is covered with a cap I, and the inside is divided into a liquid level detection chamber 6, an 11th second reservoir chamber I44+46). ing.

Six bosses higher than the above-mentioned boss l5il are formed on the earthen wall in the middle part of the cylinder body (2), and the liquid connection hole (to) is connected to the first liquid pressure generating chamber through the return hole III. It is in constant communication with Mukatsu Fukoku through the supply hole ω. Additionally, there is a grommet seal (
The other connecting cylindrical portion of the reservoir 541 is press-fitted through the connector.

Next, details of the booster section (4) will be explained with reference to FIGS. 1 and 2.

The first piston pump is one of the main components of the booster section (4), and the above-mentioned achiemulator pressure chambers are formed on the rear and side circumferences of the first piston. Located above the cylinder body (
2) is formed with a boss portion, to which the connecting member is screwed. There is a ball valve (c) and a valve spring (to) inside the boss part (f).
A check valve consisting of a
The pipe line (9) side connected to can communicate with the achiemulator pressure chamber (■). An Akie emulator (C) is connected to the pipe 8η, and a discharge port of a hydraulic pump ■υ is connected via the pipe (H). Further, the hydraulic pump g]J is driven by a motor (not shown), and its suction port is connected to the second fluid reservoir ω through a pipe (g). This reservoir ω is connected to the connection port of the first reservoir 64 (
43a). The first reservoir 5 serves as a common reservoir of hydraulic fluid for the above-mentioned mask cylinder section (3) and booster section (4), but the second reservoir (A) serves as a common reservoir for the servo section. It works to guarantee the fluid level, and even if the brake system connected to one of the reservoir chambers breaks down and leaks fluid, and it becomes impossible to supply fluid to the servo part, the hydraulic pump A sufficient amount of liquid for the servo part to operate normally is stored in the second reservoir ω.
Since it is suctioned and stored inside, this serves to operate the servo section.

A stepped hole is formed in the rear part of the first piston 4 in the axial direction, and a movable valve body is slidably inserted between the small diameter hole part ω and the medium diameter hole part. The front end of No. 7 is fitted into a small diameter hole through a seal ring disc. The small diameter hole portion (T) of the stepped hole communicates with the pressureless chamber @ via the radial through hole (122). In addition, the movable valve body @ has a through hole (97c) that is aligned and communicates with the small diameter hole (g) of the stepped hole in the axial direction.
) is formed.

The spring receiver is provided with a ring facing so that the seal ring disc is brought into contact with the step between the small diameter hole part - and the medium diameter hole part ω in the stepped hole diagram, and this and the outer periphery of the movable valve body 197). A valve spring (100) is stretched between the annular protrusion (cs7a) formed in the movable valve body and urges the movable valve body backward.

The rear end opening of the stepped hole of the first piston 4 has a sleeve (
104) is fitted with a seal ring (103) 9, which is prevented from being removed by a stopper (105). The rear end of the movable valve corporal punishment is slidable in the inner hole I/C of the sleeve (104), and the rear end is connected to the input member (9).
) is aligned with the recess (107) formed in the front end of the. The movable valve corporal punishment has an annular protrusion (97a) connected to the sleeve (
104) by abutting the front end (104a) of the
Its rearward position relative to the first piston 4 is regulated.

An input head is formed around the middle part of the movable valve body □□□ in the medium diameter hole part ω of the stepped hole, and this is formed in the first piston 4 and is connected to the akiemulator through the passage hole (101). It is in constant communication with the pressure chamber (2). Also sleeve (104
) is formed around the periphery of the communication chamber 9, which is in constant communication with the boosting pressure chamber (c). Movable valve corporal punishment annular protrusion (
97a) and the front end (to4a) of the sleeve (104) constitute a K-side supply valve, which is closed in the illustrated state, but when opened, the hole (104) formed in the sleeve (104)
9), the input chamber a communicates with the communication chamber, that is, the booster pressure chamber opening. In addition, a discharge valve is constituted by the rear end of the movable valve corporal punishment and the tapered valve seat (t07a) formed at the open end of the recess (107) at the front end of the input member (9), and the discharge valve is in the illustrated state. is in an inactive state, but according to the invention it is closed. Or they are separated by a small gap. A running hole (150) formed in the sleeve (104), an axial through hole (97c) for the movable valve corporal punishment, a small diameter hole (toward) in the stepped hole diagram of the first piston 4, and a radial through hole (122). ,
Although the reservoir side and the booster pressure chamber (c) side are able to communicate through the no-pressure chamber, the input member (9) moves forward and the valve seat (xo7a) moves behind the movable valve body (part). When pressed against the ends, communication between them is cut off. The input member (9) is biased rearward by a spring αQ stretched between the flange portion (9a) and the sleeve (104), and the lid body (6) is in contact with the rear end of the first piston α9. ), its rear position is regulated by a stopper member (106) fixed to the end face of the movable valve body (106).That is, the rear end of the movable valve body and the valve seat (106) are regulated.
7a) is regulated to be 0 or close to 0.

The hydraulic booster according to the embodiment of the present invention is constructed as described above, and its operation will be explained next.

The input member (9) moves to the left in FIG. 2 when a brake pedal (not shown) is depressed. The valve seat (r07a) formed at the front end of the valve seat (r07a) comes into pressure contact with the rear end surface of the movable valve corporal punishment, thereby closing the discharge valve constituted by these parts.

In other words, the communication room is cut off from the reservoir side.

♀---〇If the input member (9) moves further forward in this state, it will push the movable valve body (part) and push the annular protrusion (97)
a) is removed from the valve seat (XO+a). This allows pressurized fluid to be introduced into the communication room from the Akiemuleta royal family.

That is, this pressure liquid is introduced into the booster pressure chamber, and applies liquid pressure to the right end pressure receiving portion of the piston 4, thereby imparting a moving force to the left in the figure. In this way, as the input member (9) moves forward, the hydraulic pressure in the booster pressure chamber (2) increases.

Furthermore, to explain the action until the desired braking force is obtained, as the input member (9) moves forward as described above, the movable valve body 87) resists the elastic force of the valve spring (100) and moves the first piston α9. The annular protrusion (
97a) is unseated from the front end (104a) of the sleeve (104). That is, the supply valve opens, and the pressure liquid flows from the input chamber a into the pressure chamber (c) through the communication chamber. As a result, the first piston α9 receives hydraulic pressure at the right end surface of its first large diameter portion +211, and a force for moving it to the left is generated. It is assumed that when the vehicle starts running, the motor is driven and the hydraulic pump 0υ is operated at the same time as the brake starts operating. Pump (911 is driven by Akiemulator (
c) within a predetermined range of pressure, e.g. 120 to 150 Kff.
The motor is driven to store a pressure of /cd. Further, a predetermined amount of liquid is stored in the second reservoir field. The pressure liquid is transferred to the dam pressure chamber c! via the ball valve (c). It is supplied within a. The pressure of the achiemulator pressure chamber is constantly applied to the input chamber a through the through hole (101).

As the first piston 4 moves forward, the input member (9) also moves forward;
The discharge valve is closed t\. When the cup seal @ attached to the third large diameter portion of the first piston 4 and the cup seal 01 attached to the large diameter portion of the second piston 4 pass through the return hole 1115G, the first and second hydraulic pressures are Generation room +4 (
H4+1 is in a sealed state with respect to the reservoir side, and from then on,
As the piston αIK moves forward, the first and second hydraulic pressure generating chambers t41
The hydraulic pressure of 141) increases equally.

In this way, the desired brake can be applied to the vehicle.

When the desired brake is applied, the input member (9
) through the connecting member (b) and the force exerted on the input member (9) by the hydraulic pressure Pa introduced into the pressure chamber 9 are balanced, and the hydraulic pressure Pa is the first Force exerted on the right end surface of piston 4 and hydraulic pressure generated in the first hydraulic pressure generating chamber t41 P7F
The force L exerts on the left end surface of the first piston 4 is balanced,
The first piston 4 has stopped and the supply valve has also closed. That is, the annular projection (97a) of the movable valve body (part) is in contact with the front end (LO4a) of the sleeve (104), and the above-mentioned constant hydraulic pressure Pa is introduced into the pressure chamber 4. This provides a boosting effect.

When the driver returns the player pedal to release the brake, the input member (9) is activated by the hydraulic pressure in the pressure chamber and the spring (1).
It receives a spring force of 0 and moves back to the right. As a result, the recess (107) at the tip is separated from the rear end surface of the movable valve body.

That is, the discharge valve opens. The pressure liquid in the pressure chamber t21 flows into the surface of the pressureless chamber through the movable valve corporal punishment through hole (97c) and the radial through hole (122).

As the pressure of the pressure block decreases, the pressure of the first hydraulic pressure generating chamber and the spring force of the return spring 4'7) are applied to the first hydraulic pressure.
The piston head and second piston head move to the right, assume the positions shown, and the brake is released.

The return position of the input member (9) is regulated by the stopper member (105), and the recess (107) at its tip is in contact with the rear end of the Fi movable valve element sister or is in a state with almost no gap. become.

In addition, if the recess (107) of the manual member (9) is regulated so that it comes into contact with the rear end of the movable valve body (part), the piston will be moved by the pressure in the pressure chamber (c). Input member (9
), the discharge valve opens and the pressure liquid is returned to the reservoir side, so when the discharge valve closes and stops, the liquid in the main pressure chamber (2) is '<.

It can be done.

The embodiment of the present invention operates as described above, but
Furthermore, the following effects are achieved.

That is, as shown in Fig. 2, when the device is not in operation, the rear end of the movable valve body and the input member (the valve seat (107) formed in the recess (107) are in contact with each other; Since the gap is O, when applying the brake, that is, when the input member (9) starts moving, the discharge valve can be immediately closed and the supply valve can be opened, so that the brake operation characteristics are extremely good. If the distance between the rear end of the movable valve body and the valve seat formed at the tip of the input member is large as in the past, the input member must be moved considerably to bring them into contact. In other words, the brake operability was poor due to the large play, but according to this embodiment, this can be greatly improved.

Although the embodiments of the present invention have been described above, the present invention is of course not limited thereto, and various modifications can be made based on the technical idea of the present invention.

For example, in the above embodiment, a valve seat is formed by a conical recess formed at the tip of the input member as a discharge valve, and the discharge valve is constituted by this and the rear end surface of the movable valve body. However, a known valve structure can be used instead.

Further, the hydraulic booster to which the present invention is applied is not limited to the one shown in the drawings, but can also be applied to general hydraulic boosters.

〔Effect of the invention〕

As described above, according to the hydraulic booster of the present invention, the initial operating characteristics are much better than conventional ones, and the operation to obtain the desired braking force by improving the operating performance is smoother and easier. It can be made easy.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the entire hydraulic booster according to an embodiment of the present invention, and FIG. 2 is an enlarged sectional view of the booster section in FIG. 1. In the figure,

Claims (1)

[Claims] A cylinder body formed with a cylinder hole, a piston that is slidably inserted into the cylinder hole and defines a servo chamber at one end, a valve hole provided in the piston, and an external pressure of the pressure chamber arranged in the valve hole. a valve device that controls communication/cutoff to a source and a pressure release source according to an input; and a control member that fits into the valve hole and controls input to the valve device, the valve device being controlled by a spring. a valve body that is biased toward the member and movable in the axial direction; a supply valve seat provided on the inner wall of the valve hole so that the valve body can be seated;
a discharge valve seat provided on a control member so that the valve body can be seated; and a return spring that biases the control member in a direction opposite to the valve body so that the discharge valve seat and the valve body are separated from each other. In the hydraulic booster, when the control member is not in operation, the control member is engaged with the cylinder body, and the control member is moved against the valve body in a direction in which the discharge valve seat and the valve body are seated against the return spring. A hydraulic booster that is moved by